This invention relates to woven fabrics, and more particularly, it relates to fabrics woven from flat tape or tow of fiber reinforced plastic material.
Fiber-reinforced plastic structures have been used for many years with increasing success beause of their high strength, light weight and ease of fabrication compared to the wood or metal structures which they replace. Fibers such as glass, carbon and aramid are popular as reinforcement, and thermosetting resins such as polyester, phenolic and epoxy are common polymeric matrices. Such structures are disclosed by Moyer in U.S. Pat. No. 3,993,726 and by Binnersley et al. in U.S. Pat. No. 4,640,861.
Polymeric materials reinforced with continuous filaments such as disclosed by Moyer in U.S. Pat. No. 3,993,726 are used as precursors for highly-stressed parts such as aerospace components requiring the highest possible strength with the lowest possible weight. Non-uniformity of the materials comprising such parts requires that the parts be over-constructed so that the weakest will surpass the service requirements. More uniform precursor materials would yield parts having less variation in properties and would permit constructing such parts more efficiently to design criteria.
Weaving, to which this invention applies, comprises forming a fabric on a loom by interlacing warp and weft threads. The prior art includes many techniques for feeding the weft threads through the warp. Conventionally the weft is taken from a stationary package with an "over the end of the package takeoff" which results in twist being formed in the weft.
When weaving such reinforced tape in satin weave and basket weave fabric constructions under such weaving conditions the weft tape will likely have twist formed during the weaving operation. Such twist would represent an undesirable nonuniformity in the fabric. Therefore, the production of woven fabrics from tape of fiber reinforced plastic without such twisting would be highly desirable.